Conveyor belts, are usually supported on a plurality of rollers and although a conveyor belt may comprise a continuous web or a layer formed by linked elements, the forces exerted by an article supported on a conveyor belt are transferred to individual support rollers which, provide a plurality of support points constituted by the crests of successive rollers so that an article carried by a conveyor belt is effectively supported by a number of line contacts across the length of the conveyor. In the case of the conveyor belt the web is unsupported between adjacent roller crests. This situation is usually satisfactory because the article carried by the belt conveyor spans a plurality of rollers and the overall load applied to any one roller by an article is limited to a fraction of the article weight. At a loading point, however, especially if the conveyor is loaded from above rather than from an end or one side, shock loading can occur which may cause fracture of the rollers if it exceeds a critical threshold value. When belt conveyors are used to carry irregular articles such as rocks loaded from above, which may be of different size and weight as they arrive at the conveyor, there is a serious risk of damage to the rollers if these are allowed to fall onto the conveyor due to the high shock loading level of individual rollers at the contact point.
The conveyor belt may also suffer damage where items such as rocks impact onto the surface of the belt at the point of support by the rollers or may be pierced by impact between the contact points. In order to overcome this problem it is known to provide elongate supports to carry the shock loading of articles arriving from above onto a belt conveyor. Known such supports are constituted by elongate rubber blocks provided with a suitable facing, but such blocks are expensive and difficult to fit, have a short life and are generally unsatisfactory.